Matter-wave bistability in coupled atom-molecule quantum gases

We study the matter-wave bistability in coupled atom-molecule quantum gases, in which heteronuclear molecules are created via an interspecies Feshbach resonance involving either two-species Bose or two-species Fermi atoms at zero temperature. We show that the resonant two-channel Bose model is equivalent to the nondegenerate parametric down-conversion in quantum optics, while the corresponding Fermi model can be mapped to a quantum optics model that describes a single-mode laser field interacting with an ensemble of inhomogeneously broadened two-level atoms. Using these analogy and the fact that both models are subject to the Kerr nonlinearity due to the two-body s-wave collisions, we show that under proper conditions, the population in the molecular state in both models can be made to change with the Feshbach detuning in a bistable fashion.Comment: 6 pages, 5 figure

Mechanisms of Competitive Adsorption Organic Pollutants on Hexylene-Bridged Polysilsesquioxane

Hexylene-bridged periodic mesoporous polysilsesquioxanes (HBPMS) are a promising new class of adsorbent for the removal of organic contaminants from aqueous solutions. These hybrid organic-inorganic materials have a larger BET surface area of 897 m2·g−1 accessible through a cubic, isotropic network of 3.82-nm diameter pores. The hexylene bridging group provides enhanced adsorption of organic molecules while the bridged polysilsesquioxane structure permits sufficient silanols that are hydrophilic to be retained. In this study, adsorption of phenanthrene (PHEN), 2,4-Dichlorophenol (DCP), and nitrobenzene (NBZ) with HBPMS materials was studied to ascertain the relative contributions to adsorption performance from (1) direct competition for sites and (2) pore blockage. A conceptual model was proposed to further explain the phenomena. This study suggests a promising application of cubic mesoporous BPS in wastewater treatment

Victim sensitivity and altruistic behavior in school: mediating effects of teacher justice and teacher-student relationship

The current study aimed to explore how victim sensitivity influenced altruistic behaviors in school and to explore the mediating roles of teacher justice and teacher-student relationship. In 2018, we recruited 1,856 Chinese adolescents including 989 fourth graders (M = 10.35, SD = 0.56) and 867 eighth graders (M = 15.57, SD = 0.91), and the participation rate was 100%. Participations completed the self-report victim sensitivity scale, the teacher justice scale, the teacher-student relationship scale, and the altruistic behavior toward classmate scale. Structural equation modeling (SEM) indicated that victim sensitivity had a direct negative effect on altruistic behavior in school, but this relationship was mediated by teacher justice. There was also a mediated path between teacher justice and altruistic behavior by way of teacher-student relationship. These findings suggested possible mechanisms to explain the relationship between victim sensitivity and altruistic behavior and provided new directions for intervention

INTERACTIONS AND INFLUENCES ON COAL MINERS' SAFETY ATTENTION: AN EVALUATION USING IMPROVED DEMATEL-ISM

In coal mining, the myriad of factors influencing miners' attention to safety necessitates deeper exploration. Particularly, discerning the significance and interplay of these factors offers crucial insights into the actual disparities in miners' safety attentiveness. Yet, a limited number of comprehensive studies address this dimension. Thus, an advanced Decision Making Trial Evaluation Laboratory-Interpretive Structural Model (DEMATEL-ISM) has been employed to probe the determinants impacting coal miners' safety focus and the mechanisms underpinning these interactions. The objective is to provide strategies that could diminish the occurrence of minor accidents. Results revealed that there are 9 causative factors and 6 resultant factors shaping the coal miners' attention to safety. Within the structural model of these factors, three layers and seven levels were identified. Notably, the intricacy of relationships among these factors was found to be profound. Emphasis is recommended on the management of these intricate deep-level causative factors boasting high driving power, and mid-level resultant factors characterized by both substantial driving force and dependence

cis-4-(Tosyl­oxymeth­yl)cyclo­hexa­ne­carboxylic acid

The title compound, C15H20O5S, is an inter­mediate in the synthesis of novel amino­carboxylic acid derivatives. The cyclo­hexane ring exhibits a chair conformation. In the crystal structure, adjacent mol­ecules form dimers via O—H⋯O hydrogen bonds

The Physical Origins of Entropy Production, Free Energy Dissipation and their Mathematical Representations

A complete mathematical theory of nonequilibrium thermodynamics of stochastic systems in terms of master equations is presented. As generalizations of isothermal entropy and free energy, two functions of states play central roles: the Gibbs entropy $S$ and the relative entropy $F$, which are related via the stationary distribution of the stochastic dynamics. $S$ satisfies the fundamental entropy balance equation $dS/dt=e_p-h_d/T$ with entropy production rate $e_p\ge 0$ and heat dissipation rate $h_d$, while $dF/dt=-f_d\le 0$. For closed systems that satisfy detailed balance: $Te_p(t)=f_d(t)$. For open system one has $Te_p(t)=f_d(t)+Q_{hk}(t)$ where the housekeeping heat $Q_{hk}\ge 0$ was first introduced in the phenomenological nonequilibrium steady state thermodynamics. Entropy production $e_p$ consists of free energy dissipation associated with spontaneous relaxation, $f_d$, and active energy pumping that sustains the open system $Q_{hk}$. The amount of excess heat involved in the relaxation $Q_{ex}=h_d-Q_{hk} = f_d-T(dS/dt)$.Comment: 4 pages, no figure

Spectral Energy Distributions and Age Estimates of 172 Globular Clusters in M31

In this paper we present CCD multicolor photometry for 172 globular clusters (GCs), taken from the Bologna catalog (Battistini et al. 1987), in the nearby spiral galaxy M31. The observations were carried out by using the National Astronomical Observatories 60/90 cm Schmidt Telescope in 13 intermediate-band filters, which covered a range of wavelength from 3800 to 10000A. This provides a multicolor map of M31 in pixels of 1.7"*1.7". By aperture photometry, we obtain the spectral energy distributions (SEDs) for these GCs. Using the relationship between the BATC intermediate-band system used for the observations and the UBVRI broad-band system, the magnitudes in the B and V bands are derived. The computed V and B-V are in agreement with the values given by Battistini et al. (1987) and Barmby et al. (2000). Finally, by comparing the photometry of each GC with theoretical stellar population synthesis models, we estimate ages of the sample GCs for different metallicities. The results show that nearly all our sample GCs have ages more than 10^{9} years, and most of them are around 10^{10} years old. Also, we find that GCs fitted by the metal-poor model are generally older than ones fitted by the metal-rich model.Comment: 38 pages, 7 figures will appear in the February 2003 issue of A

The Impacts of Swimming Exercise on Hippocampal Expression of Neurotrophic Factors in Rats Exposed to Chronic Unpredictable Mild Stress

Depression is associated with stress-induced neural atrophy in limbic brain regions, whereas exercise has antidepressant effects as well as increasing hippocampal synaptic plasticity by strengthening neurogenesis, metabolism, and vascular function. A key mechanism mediating these broad benefits of exercise on the brain is induction of neurotrophic factors, which instruct downstream structural and functional changes. To systematically evaluate the potential neurotrophic factors that were involved in the antidepressive effects of exercise, in this study, we assessed the effects of swimming exercise on hippocampal mRNA expression of several classes of the growth factors (BDNF, GDNF, NGF, NT-3, FGF2, VEGF, and IGF-1) and peptides (VGF and NPY) in rats exposed to chronic unpredictable mild stress (CUMS). Our study demonstrated that the swimming training paradigm significantly induced the expression of BDNF and BDNF-regulated peptides (VGF and NPY) and restored their stress-induced downregulation. Additionally, the exercise protocol also increased the antiapoptotic Bcl-xl expression and normalized the CUMS mediated induction of proapoptotic Bax mRNA level. Overall, our data suggest that swimming exercise has antidepressant effects, increasing the resistance to the neural damage caused by CUMS, and both BDNF and its downstream neurotrophic peptides may exert a major function in the exercise related adaptive processes to CUMS